Tractive wheel



ill

Patented Mar. 31, 1925.

PATENT QFFQE.

CLARENCE LEE POOLE, OF PONTIAC, MCHIGAN.

TRACTIVE WHEEL.

Application filed December 13, 1921.

fou/ fro/1,0m it may concer/1i.'

Be it known that I, @Larnaca` Lian PooLn, a citizen of the United States, and resident of Pontiac, in the county of Oakland and State of Michigan, have invented a new and improved Tractive lllheel, of which the following is a full, clear, and exact description.

My invention relates to a tractive or bull wheel, which is primarily adapted for 'use in connection with tractors and similar types of vehicles.

It is a well appreciated fact that vehicles which are used to traverse a rough surface, as in the case of t'actors, etc., present considerable difficulty. More particularly it has been noted, that a tractor, having a plural-A ity of driving wheels, although operating efliciently on a fairly even surface, and while advancing along a substantially straight line, will not operate in a'satisfactory manner when traversing an extremely rough surface or when turning in a circle.

This latter defect is to be attributed to the fact that the tractive wheels will travel in courses of varying acuteness, and due to the action of the differential there will be a loss of power. To overcome this defect it has been suggested that a single tractive or bull wheel be utilized, but the direction of movement of this Iwheel has had to be changed by main force, and also that when the wheel was moved out of a straight line slippage occurred, resulting in a loss of tractive power.

Thus it is an object of my invention to provide a tractive wheel adapted for use in connection with any type of vehicle, but

particularly intended to be associated with vehicles of the tractor class, and by means of which a vehicle will be capable of traversing a relatively uneven ground without difliculty, and without danger of tipping.

further object of my invention is the cmisti'uction of a device of the character stated which after moving over obstacles, or an uneven surface, will right i -,lf automatically, and without the necessity of the operatrn' giving this device his constant attention.

Still another object of this invention is the provision of a wheel which may be substituted for the two driving wheels now contr monly used, in connection with tractors, and which when utilized will permit of the elimination lof the differential or compensating Serial NO. 522,112.

axle, aside from the fact that the said wheel course. f

Among further objects of this invention are the construction of a tractivc wheel which when utilized Ain connection with a vehicle will enable the latter to have an eX- tremely short turning radius, the wheel being capable of having incorporated with it, a power unit which will thus provide a heavy propelling wheel; and

- Other objects of this invention will become apparent in the annexed specification taken in connection with the drawings, which latter illustrate one practical embodiment thereof, and in which;

Figure l is a side elevation of a tractive wheel embodying my improved construction and showing the same associated with an operators seat and supplementary steering wheels.

Figure 2 is a rear view thereof.

Figure 8 is a side elevation of the said wheel showing the same detached.

F ignre 4 is a transverse sectional view of the said wheel.

Figure 5 is a side elevation of the wheel, and

Figure 6 is an enlarged sectional view of a detail of construct-ion.

The essence of my invention consists in the provision of a wheel of the type specitied, which will in normal travel assume a cylindrical shape, but when negotiating a turn will assume a'conical shape.

Thus as in Figure it will be seen that the reference numeral l() indicates the body of the wheel which is preferably in the form of a pair ofv truncated cones having a comg.'

mon base, it being noted that an annular rib in the form of a rail l1 is interposed between the base portions of these cones, and serves a purpose hereinafter specified.

lVith a view of providing tread for the body of the wheel, I utilize panels or sections 12, and it will be noted in the embodiment illustrated, that these panels are hexagonal. Each tread section has the outer surface thereof convexly curved trans versely thereof. Also it will be seen that the rail ll serves as a mounting for these panels in that the saine are pivotally associated with the said rail at points preferably intermediate their extremities, as has been indicated at 18,

Thus assuming that the fait i5 iffti CII around its axis, as in Figure Il, and that the latter is retained in a horizontal plane, it will be appreciated that the panels will each remain in a substantially horizontal plane. However, if the body 1() is inclined as in Figures 2 and 3, the panels will swing so as to present a virtually unbroken tread surface extending Yfrom their adjacent outer extremities to the rail 11.

Also a shaftllc extends through the body 10, and this shaft serves as an axle for the wheel, and with a view ot synchronizing the movement o1: all of the panels, a spider or hub 15 is associated with the said shaft, and carries a number of arms 16, which arms have one of their ends pivotally attached to the spider, their bodies extending through slots 17 in the periphery of thebody 10, their opposite ends being pivotally connected to the under side of the panels 12. It will be seen from the foregoing that it one olf the panels is swung inwardly that this mot-ion will result in an inward push upon the arm 16 associated with this panel, in turn causing a rotation of the spider 15 around the shaft let, and consequently causing all ot the other arms to be retracted, thus swinging all ot the panels to a position corresponding to that of the first mentioned panel.

The foregoing constitutes the essence et my invention, and numerous departures in construction may readily beV resorted to. However in the embodiment illustrated, it will be noted that a rigid yoke 18 is provided, the arms of which are keyed to the shafts 1%-, as at 19. Also the chassis 20 which mounts the drivers seat 21, and controls 22 carries a steering wheel 23. rllhis wheel when rotated, serves to revolve a gear Q4 which meshes with an arcuate rack 25, the latter 'being fixedly secured to the body of the yoke 18, and extending between the links 2G which have their upper ends pivotally connected to the yoke, their lower ends being attached to the chassis Q0.

Thus upon the steering wheel 2S being rotated itwill be obvious, assuming that the axle remains in a relatively fixed plane, that incident to the resultant movement of the rack 25, the yoke 18 will be tilted, as has been shown in Figure Q, and incident to the rigid construction of this yoke, the shaft 11- and consequently the body of the wheel will also be tilted, this operation immediately resulting in a swinging of the` panels 12 in the manner aforedescribed.

Upon these panels swinging the circumference of one edge of the wheel will be constrieted, while that of the opposite edge will be greatly enlarged, thus causing the wheel to follow a circular path upon its body being revolved around its axle.

it will be obvious that this action of the parts will result in a steering of the vehicle but with a view of providing an extremely short turning radius for the saine, it will be noted that arms 27 have one of their ends attached to the links 2G while their opposite ends are secured to steering knuckles 228, the latter being provided with the conventional stub shafts 29 carrying wheels $50, of any suitable character. By this construction it will be obvious that the vehicle will be supported and steered at three points enabling the saine to be turned in an exA tremely short radius.

It will further be noted in the embodiment illustrated, that a self-contained power unit is associated with the wheel, and this unit may be of any desirable type such as that which includes a motor 31, secured to the axle 11 and serving to drive a gear 32, which latter meshes with an internal gear tl?, lixedly secured to the body 10, it being thus obvious that upon the motor 31 being operated that the latter, and the shalt ll will be held from revolving by virtueI et" the connection 19 and thus the gear 32 will cause the gear 33, and consequently the body 10 carrying the panels to revolre around the motor. lt is to be noted in this connection that the operation of the motor may be controlled trom the drivers seat by means ot' the members 22 atoredescribed, the connection between these members and the throttle, spark, etc., being accomplished by any suitable type ot linkage 341, as has been shown in Figure 1.

Finally with a view ot properly supporting the axle and motor with respect to the body ot the wheel, Lattention is invited lo Figures 1 and 3 in which it will be seen that members 35 in the nature of spring shock absorbers extend between the inner face ot the body 10 and diametrically opposite arms 36, secured to the spider 15, rotatably carried by the axle 1a. Thus it will be seen that the axle will have what might be termed a floating suspension so that any sudden shocks to which the bozlv ot' the wheel might be subjected, will not be transmitted in Ylull violence to the axle, and parts carried thereby. The members 35 also 'function as retractile springs and are arranged in sets oi two spring members, the respective spring members of each sel being pivotally connected at their inner ends with the arms 36 at points spaced approximately 180 apart and heilig attached at their einer ends to the body 10 at points spaced les than 1800 apart. Balanced torques thus are exerted on the spider or hub 15 when the latter is in normal position, tending to hold the hub 15 against rotational move ment about the axis oi the shalt 11i independently oc the body 'lO and insuringl the return et' the hub to normal position when it has been rotated therefrom through the action of the arms 16. rl `he hub is in ifi ill)

normal position when the arms 16 carried thereby are in such positions that the respective tread sections to Which the arms 16 are attached at their outer ends are disposed substantially parallel to the axis ot rotation ot' the hub 15 and in the aggregate comprise a tread of substantially cylindrical term. lf also term this last mentioned position of the. thread sections 12 the normal position thereof and it therefore will be ap parent that the thread sections 12 Will be yieldingly held in normal position until moved there't'rom by the application ot an external torce and that the tread sections will be returned instantly to normal position as soon as the external torce has been removed. To t'urther support the member 81 and to prevent the same being subjected to extremely rough usage it will be noted, as iu Figures 4 and 5 that a T shaped brace 37 is tixedly carried by the axle 14 and primarily serves as a mounting for the crank shaft 38 o1 the said motor.

,Having one ot its ends connected to the cylinders, its opposite end being connected adjacent the outer end of one of the arms ot the T shaped brace 37 is a quarter elliptic spring 3S) and it Will be obvious incident to the strain that this spring will serve as an additional support for the motor, and that the said spring will also serve to absorbV shocks in a vertical plane, incident to `the tact that the bridge 40 carried by the axle 14 engages said spring, it being further noted, that incident to this construction the spring will retain the gear 32 at all times in mesh with the gear 33. Having one of its ends secured adjacent the end of the second arm of said T shaped brace is a double acting spring element 41 which latter has its body pivotally carried by an extension 42 projecting in a direction opposite from the direction in' Which the bridge 40 extends.

The construction ot this member is preterably such as has been shown in Figure 6, in which it will, be noted that a casing 48 is provided through which a rod 44 slidably extends, one end of this rod carrying a head 45 in slidable engagement with a sleeve 46. A similar' head 47 is associated With the body ot the rod 44, and co-operates with a second sleeve 48 ctn-responding to the sleeve vl-t. and interposed betav'een these two sleeves, and disposed within the casing 43 is a compression spring 43). Now assuming, as has been atoredeseribed. that the rod 43 has its outer end connected to one ot the arms of the brace 37, its body being pivotally supported by the element 42, it Will be understood, that iit' the base moves with respect to the elementI 42, in such a manner, as to effect a projection of the rod 44, that the head 47 Will slide freely Within the sleeve 48, but the head 45 will engage the sleeve ,the motor by lateral movement.

lregardless as to the tact that the rod is projected or retracted, the spring will be pressed, and this element will `act as a shock absorber to cushion anyv sudden shocks Which might be imparted to the parts ot In other Words, upon the. tractive Wheel encountering sudden obstacles, steep grades, or moving .dovv'n sharp declines, etc. the member 41 Will lact to absorb any strains Which would otherwise be passed along to the parts of `the motor, and ultimately result in damage to the latter.y

Thus it will be understood, that all of the objects set forth in the preamble of this specification are accomplished, in that it Will be obvious that by meansof my improved construction a Wheel is capable of negotiatmg and pulling over a surface of extremely uneven character. Also the Wheel itself may serve as the sole steering unit in Which application it will be extremely effective, incident to the fact 4that the circumference of one side edge may be greatly increased or diminished, With respect to the second side edge automatically, and also at the will of the operator, it being further understood, that when the said Wheel is coupled withy an auxiliary steering apparatus, such as has been shown in the embodiment illustrated, vthe vehicle is capable of turning in an extremelyl short radius. Also a Wheel of my improved type preferably embraces a selfcontained power unit, and is of such relatively simply construction as to permit of its being manufactured at an extremely nominal figure. Further, it will be seen th at incident to the fact that but a single Wheel is necessary for steering purposes, and that this Wheel assumes a conical shape, when tilted, that the differential or compensating axle may be dispensed With.

It will tinally be appreciated that numerous modifications of structure might readily be resorted to Without in the least departing t'rom the scope ot my claims, which are:

I claim: f

1. AA Wheel including an annular body, a tread comprising a plurality of sections, each pivotally supported intermediate its ends on said body, a hub, and means connecting said tread sections to said hub and holding said tread and said hub continuously in concentric relation to each other While permitting limited relative rotational movements said hub and tread.

sion of the circumference thereof at one end and of simultaneous regular contraction ot' the circumferenzie thereof at its other end, as and for the purpose described.

l2. In a wheel, a tread substantially circular in cross sectional contour and normally uniform in diameter throughout its length, said tread being capable of radial expansion at one end and of simultaneous radial contraction at its other end, While remaining circular in cross sectional contour at any point along its length.

1.3. lin a Wheel, an annular tread supported along a line coinciding with a circle .located midway between the ends olf the tread7 the circumference of said tread at ono olf its ends normally being equal to the circumference of the tread at its other end and said tread being adapted to be expanded regularly :from said line of support to one of its ends and contracted regularly from said line of support to its opposite end.

lei. In a Wheel, a tread comprising a plurality of segmental sections arranged in the iorm oi an annulus7 said sections being pivotally' supported intermediate their ends` Vsuch manner that said tread will assume a substantially cylindrical shape so long as the radial pressures on said sections at op posite sides of said line of pivotal support are equal and will assume a substantially frusto-conical shape when the radial pressures on any one of said sections at opposite sides of said line of pivotal support are unequal,

l5. In a Wheel, a substantially annular tread comprising a plurality oit segmental sections connected together as to present a practically continuous tread surface and normally to have substantially the same cir cumference along its entire length, said tread being adapted to change in shape in response to unequal pressures at dii'erent points along its length to vary the circumference thereof at different points along its length.

CLARENCE LEE POOLEL 

